The galactic habitable zone and the age distribution of complex life in the Milky Way

C Lineweaver, Brad Gibson

Research output: Contribution to journalArticle

203 Citations (Scopus)


We modeled the evolution of the Milky Way Galaxy to trace the distribution in space and time of four prerequisites for complex life: the presence of a host star, enough heavy elements to form terrestrial planets, sufficient time for biological evolution, and an environment free of life-extinguishing supernovae. We identified the Galactic habitable zone (GHZ) as an annular region between 7 and 9 kiloparsecs from the Galactic center that widens with time and is composed of stars that formed between 8 and 4 billion years ago. This GHZ yields an age distribution for the complex life that may inhabit our Galaxy. We found that 75% of the stars in the GHZ are older than the Sun.
Original languageEnglish
Pages (from-to)59-62
Number of pages4
Issue number5654
Publication statusPublished - 2004
Externally publishedYes


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